Required Operations

The flow chart shows the general descriptions of the REQUIRED OPERATIONS. These "REQUIRED OPERATIONS" are as follows:

1. Check for the installation of the previous emission recall completed label (EMR-90-002). If the label is found on the hood, proceed to step 2 below. If the EMR-90-002 Emission Recall Completed Label is NOT found, do EMR-90-002. While performing EMR-90-002, install the front catalytic converter which is contained in EMR-92-008 emission kit and also replace the Jet Mixture Solenoid valve with the new green valve. Check CO level at 2,500 RPM. If the CO reading is greater than 1.2% at 2,500 RPM, visually check the new Jet Mixture Solenoid Valve installation for misalignment. If the Jet Mixture Solenoid Valve is correctly installed, replace it with another new green Jet Mixture Solenoid Valve. If the CO is still greater than 1.2%, refer to the 1985 Truck Service Manual for troubleshooting procedures which begin in Section 14. The EMR-90-002 Emission Recall Bulletin can be found in the 1990 Technical Service Bulletin Manual beginning on Page 367. After completing EMR-90-002 proceed to step 12.

2. Clean the carburetor using carburetor spray cleaner.

3. Check the size of the primary main air jet. Replace the primary main air jet if the size is "80".

4. Inspect the exhaust manifold heat protector. Check the exhaust manifold and the heat protector for evidence of exhaust leakage. Replace the exhaust manifold only if leakage is evident.

5. Replace the front catalytic converter.

6. Check the installation of the choke shim on the carburetor. If the choke shim is missing, obtain the EMR-90-002 emissions kit, install the choke shim contained in the EMR-90-002 emissions kit.

7. Replace the Jet Mixture Solenoid Valve.

8. Check for the installation of modified vacuum hoses. If the vacuum hoses assembly is missing, install the vacuum hoses contained in the EMR-90-002 emission kit.

9. Check the idle speed and ignition timing. Adjust if necessary.

10. Check the CO (Carbon Monoxide) level at 2500 RPM.

11. Check the existing Service Label. The part number on the label should be MD164141. If not, install the Service Label contained in the EMR-90-002 emission kit.

12. Complete and affix the "EMR-92-008 Emission Recall Completed" Label.

13. Complete and sign the EMR-92-008 emission checklist (included in the EMR-92-008 emission kit). Attach the checklist to the repair order.

14. Complete a Vehicle Emission Recall - Proof of Correction form.